Radio receiving apparatus



Jan. 13, 1942. VAN LAMMEREN ETAL 2,270,176

' RADIO RECEIVING APPARATUS Filed Sept. 2 6, 1939 s Sheets-Sheet 1 Fi .v

L 3/ 3&5: 34 a; 36 2732 as INVENTORS JOIMNNFSA. VAN IIMMFRE/l, .llFXVJIVDIM,

u c ATTORNEQY Jan. 13, 1942. J. A. VAN LAMMEREN ETAL RADIO RECEIVINGAPPARATUS Filed Sept. 26, 1939 3 Sheets-Sheet 2 3 Sheets-Sheet 3 m W 1W/A Jam/mm M/YMMMI/V, an mum, BY u/u/zzmuu/ J. A. VAN LAMMEREN ETALRADIO RECEIVING APPARATUS Filed Sept. 26,- 1939 Jan. 13, 1942.

J$l 8%86 9 19; T97 96 receiver proper.

Patented Jan. 13, 1942 RADIO RECEIVING APPARATUS Johannes Antonius vanLammeren, Alexis van Dam, Wilhelmus Lambertus Leonardus Vivie,

and .Gunnar-Borge Kniis, Eindhoven, Netherlands, assignors, by mesneassignments, to Radio Corporation of America, New York, N. Y., acorporation of Delaware Application September 26, 1939, Serial No.296,57

In Germany September 26, 1938 4 Claims. 01. 172-239) The presentinvention relates to a remote control arrangement for radio receivingapparatus provided with push button tuning.

It is an object of the present invention to provide an arrangement fortuning a radio receiving set from a remote point by controlling from theremote point the push buttons or keys in the According to the inventionthis object is achieved by providing the receiver proper with a numberof keys each of which corresponds to one of the predetermined stationsand which can be pressed either each through the intermediary of anelement mounted on a shaft, or individually through a number of elementswhich are provided on a shaft and radially displaced relatively to oneanother; this shaft is driven from a motor which is put into servicesimultaneously witha. selective device upon operating the stationselector, said selective device causing only the key to be pressed whichcorresponds to the desired station.

In one form of construction of the invention the keys provided in thereceiver proper are arranged in a row and parallel with this row isprovided a shaft to which-are secured a number of cams by means of which.upon one revolution of the shaft the keys are pressed successively.

In another form of construction of the invention the keys provided inthe receiver proper are arranged about a shaft carrying a cam by whichthe keys are pressed successively upon one revolution of the shaft.

The selective device preferably consists of a row of contacts each ofwhich corresponds to one of the keys provided in the receiver proper andalong which travels a contact arm which is driven from the motor andruns. in synchronism with the said shaft; upon operation of the stationse-, lector one of the contacts receives a potential different from thatof the other contacts, the

. said shaft being stopped as soon as the contact reaches the contact inquestion.

In this case the motor may, for instance, be connected as an electricbrake, as soon as the contact arm reaches a contact having a potentialdifferent from that of the other. contacts. In a third form ofconstruction of the invention each key provided in the receiver propercarries a member which can be adjusted by means of a magnet; uponchoosing the station corresponding to the key in question this magnet isenergized and shifts the member so that the key is pressed through theintermediary of the element and of the member.

The invention will be more clearly understood by reference to theaccompanying drawings .representing, by way of example, some forms ofconstruction thereof.

Figures 1 and. 2 are wiring diagrams of one form of constructionaccording to the invention.

Fig. 3 shows schematically the mechanical part of this form ofconstruction.

Fig. 4 is a detail view of a circuit arrangement for tuning by means ofpush buttons.

Fig. 5 shows a secondform of construction of the invention, whereasFigs. 6 and 7 represent a third form of construction.

Fig. 1 shows a keyboard 4| for remote control which comprises a numberof press buttons 31", 308-4, etc, arranged to operate switches l, 2-5,etc. by means of which a number of station selecting keys 3|v to 40provided in a receiver.

proper of the push button type can be operated through the operation ofa motor 42. In the form of construction in question the motor 42 is alsoadapted to operate the tuning means.

For operating the keys a cam shaft is provided which is denoted by 43and the number of cams 2| to 30 provided thereon corresponds to that ofthe keys 3! to 40. These cams are radially shifted with respect to eachother so that upon rotation of the shaft 43 the keys 3| to 40 aresuccessively depressed by the cams 2| to 30. The cams are so spaced thatthere is never more than one key depressed at any one time. Thus theposition of the shaft 43 determines which key is depressed and to whatstation the receiving set is tuned, the adjustment of the shaft 43 tothe position corresponding to the desired station is effected by meansof the motor 42. The latter must be capable of actuating the shaft 43and must consequently be put into service on depressing a press buttonand, after the key corresponding to the desired station has beendepressed through the intermediary of the cam shaft 43, it must bedisengaged from the shaft 43 or thrown out. Since in the form ofconstruction described above, as has already been stated, the motor 42also drives the tuning means, a mechanical coupling must be provided atleast between the cam shaft 43 and the motor 42, which coupling can beengaged and disengaged. Moreover, it is desirable that the mechanicalcoupling between the motor and the tuning means may be engaged anddisengaged.

Upon pressing one of the press buttons three operations mustconsequently be effected, viz.:

The mechanical coupling between the motor 42 and the tuning means mustbe interrupted;

A mechanical coupling must be established between the motor 42 and thecam shaft 43; and,

The motor 42 must be put into service.

For carrying out these operations a relay 44 is provided which effectsthe required electric operations as well as the required mechanicaloperations. Relay 44 is arranged so as to operate the change-overcontacts 45 and 45, and also to shift the toothed wheel on the shaft 3|9of the motor 42 against the action of a spring 8|8.

The toothed wheel 58 meshes with the toothed wheel 5| mounted on the camshaft 43 if the relay 44 is energized, however if the relay 44 is notenergized, toothed wheel 59 meshes with wheel 52 which is mounted onshaft 32| oi the variable condensers 53, 54 and 55.

The cam shaft 43 has mounted on it a contact arm 41 which is arranged totravel over a number of contacts II to 29.

The ten contacts I to 29 are connected through ten conductors (onlythree are shown in Figure 1 so as to simplify the description) to thepress button operated switches 2-5 etc., associated with the keyboard4|. The press buttons (see 381, 388, and 3| I) are furnished with alatching mechanism 303, 3|5 which holds any depressed push button in thedepressed position and upon depressing a push button releases anypreviously depressed push button.

The latching device operates a contact 48 so that upon depression of oneof the press buttons contact 48 is closed momentarily due todisplacement of lock bar 303 to the left.

If one of the press buttons, for instance, the press button 3corresponding to switch 5 is depressed, the contact 48 is closedmomentarily by the latching device 393, due to which a closed circuitensues through a source of potential'connected between the terminals 58and 51, an incandescent lamp 49, the relay 44, the latching contact 48,and back again to the terminal 51, thus causing the relay .44 to becomeenergized thereby attracting its armature 3". In this way contact 48 isclosed and since contact 46 is connected in parallel with the latchcontact 48 relay 44 remains energized despite the opening of switch 48.As has already been stated attraction of the armature of the relay alsoshifts gear 58 out of engagement with gear 52 and into engagement withgear 5| thereby disengaging the motor 42 from the variable condensers53, 54 and 55, and coupling the motor to the cam shaft 43. Also, themotor 42 is put into circuit by changing over the change-over contact 45from the position shown to its other position, the motor being fed fromthe alternating current mains connected between the terminals 58 and 59.The motor 42 thus begins to operate in a predetermined direction andactuates the cam shaft 43 through the intermediary of the toothed wheels50 and 5|, the keys 3| to 49 being successively depressed by the cams 2|to 30, whereas the contact arm 41 travels over the contacts II to 29.

On reaching the contact l5, which is connected to the closed switch 5the relay 44 is short-circuited through the switch5, the contact I5 andthe contact arm 41. The lamp 49 constituting a series-resistance thenlights.

The relay 44 is cut out and changes over the -motor 42 upon thechange-over contact 45 resuming its left hand position which is itsposition of rest- Furthermore, the mechanical coupling rupted and themechanical coupling between the motor 42 and the variable condensers isreestablished.

The key corresponding to the press button 5 has been depressed by thecorresponding cam 25 in the reached position of rest of the cam shaft43. This depressed key 35 initiates the tuning operation.

Depression of key 35 acts through the mechanism shown in Fig. 4 anddescribed in more detail hereinafter, to cause the motor 42 to operateand bring the variable condense-rs into the desired position, theposition of the selected change-over contact 50 shown in Fig. ldetermines the direction in which the tuning means is driven by themotor.

It should be understood that while only one of the devices 50, 8| and 62has been shown, there are, in fact, ten such devices in the embodimentillustrated; that is, one for each of the ten push buttons 3| through40.

Fig. 2 represents a simplified construction of the circuit arrangementshown in Fig. 1, corresponding parts of the circuit bearing the samereference numbers. The differencebetween the circuit arrangements shownin Figs. 1 and 2 consists in that in Fig. 1 the depression of one buttonbrings about the closure of a switch, whereas in Fig. 2 the depressionof one of the buttons between the motor 42 and cam shaft 43 isinteropens a switch.

In this manner the construction shown in Fig. 1 is simplified in thatthe latch contact 48, as well as the contact 46 which is operated by therelay 44 and acts in parallel with the latch contact 48, can bedispensed with. Since, moreover, the relay 44 is not short-circuited, asis the case in Fig. 1, but is put out of circuit, the incandescent lamp49 may be omitted, thus obtaining a saving in energy.

The contact row H to 20 shown in Fig. 2 differs from the row bearing thesame reference numbers and shown in Fig. 1 only in that the contacts Hto 20 in Fig. 2 have a very small intermediate space such that thecontact arm on passing from one'tothe other contact is connected to bothcontacts.

All of the contacts II to 29 are connected respectively through theswitches to It! operated by the press buttons and through the relay 44to the terminal 51. The contact arm 41 connects with the terminal 58.Between these terminals 55 and 51 is connected the supply for the relay44. Consequently, the relay 44 is de-energized only if the contact arm41 reaches a contact which is connected to an open switch. If, forinstance, the press button 5 is depressed the switch 5 is opened and thecontact |5 insulated. On operating the press button 5 the press buttonalready depressed at this moment is released, the switch correspondingto this press button is closed and the contact of the row II to 29corresponding to this switch is connected to the relay 44. In thismanner a closed circuit ensues from the terminal 55, through the contactarm 41, the last mentioned contact and corresponding switch through therelay 44 back to the terminal 51. The relay 44 is energized and performsthe same functions as described already by reference to Fig. l. Thecontact arm 41 moves until the con tact I5 is reached. The currenttraversing the relay 44 is then interrupted owing to which the contactarm 41 comes to a standstill, whereas the relay 44 now de-energizedeffects the further required commutations.

Fig. 4 illustrates how the variable condensers can be brought into apredetermined position. The condenser shaft has adjustably mounted on ita disc I I2, provided with two peripheral edges having a diflerentradius which edges each extend, for instance, through 180 and areseparated from each other by a cavity 3, viz. the

' peripheraledge III having a larger radius and the peripheral edge I33having a smaller radius. A spring 233 clamped at a point 232 carries aIeeler II3 whose bottom side bears on' one of the peripheral edges IIIor I33 if the spring 233 is depressed. The cam 25 acts on a lever 35which is pivoted at 233, it being remarked that a plate spring 243provided between the lever 35 and the spring 233 exerts a downwardlydirected pressure on the spring 233 if the lever 35 is depressed by thecam 25.

Furthermore two contact springs I43 and I45 are provided which arefurnished with contacts 3| and 62 and, as shown in Figs. 1 and 2, areconnected to two points of the motor winding;

Between the contacts 6I and 62 there is provided a contact 63 whichalternatively bears on the contacts 6I and 62 and is supported in aninsulated manner by aprojecting part I44 provided on the spring 233. 1

Another projecting part I43 provided on the spring 233 is locatedbetween two contact springs I41 and I42 and, in the position of restillustrated, it spaces from each other the contacts 236 and 231 providedon the contact springs HI and I42. Even in the lowest position of thepro- Jecting part I43 the switch 236, 231 constituted by these contactsis open. The stator of the tuning motor is equipped with two windingswhich are wound in opposition and'are spatially displaced with respectto one another. The mains voltage is connected between the junction ofthese windings and contact spring I, whereas contact spring I42 isconnected to a contact 63. The two remaining ends of the motor windingsare connected to the contact springs I43 and I45 and interconnectedthrough a condenser. As a result 01 this the motor, if the switch 236,231 is closed and the contacts 63 and 6| touch each other, will operatein one direction, whereas if the contacts 63 and'62 touch each other itwill operate in the other direction.

If in the illustrated position the lever is depressed by the cam 25 thespring 243 acts on the spring 233 so that the latter sags until thefeeler II3 bears on the peripheral edge I33 of smaller radius below thisfeeler. When the projecting part I43 descends the switch 233, 231 isclosed and at the sametime a connection is established between thecontact 63 the contact spring I42 connected thereto ..and the contact32. In this case the motor is fed and operates in such a direction thatthe cavity II3 moves towards the feeler I I3. At the moment at whichthey reach each other the Ieeler II3 snaps into the cavity I I3 due towhich the switch 233, 231 is opened and the disc is mechanicallystopped.

If thelever 35 were depressed at the moment at which the feele'r I I3 isopposite the peripheral edge III of larger radius the teeler II3 mightbe depressed only over a smaller distance than in the first mentionedcase. The switch 233, 231 'is now closed, it is true, but the connectionbetween the contacts 33 and 3| is not interruptedso thit"in"this-casethe motor operates in the other direction until the feeler II3 snapsinto leaves again the cavity H3.

the cavity I I3 and the motor is thrown out in the manner set out above.

A device (not represented) makes that it another lever is depressed, thelever 35, which remains in the depressed position due to the depression,is released so that the feeler H3 also Fig. 5 shows another form orconstruction of the invention, In this form or construction the tuningmeans consist of a number of slide condensers one of which isrepresented in the drawing and designated by I63. The capacity variationis effected by displacement of the rod I6I in a' longitudinal directionagainst the force of a suitable returning spring (not shown) by pushingagainst a plate I62 secured to the rod The pressure on the plate I62 mayoccur either by means of a number of adjustable pins I63, I64 ofdiiIerent length or by means of a rod 65 which by turning a knob 66 canbe moved upwards and downwards in a nut 61/ by means of a screw threadwhich may have a variable pitch.

When tuning by means of a motor the knob 63 is drawn out as a result ofwhich the nut 61 closes the contact 63 and is kept in place by thespring 63. In this case the rod 65 stands free from th plate I62,whereupon the condenser can be adjusted with a motor 13 by means of thepins I63, I64. The motor 13 is mechanically coupled by means of atoothed wheel H to a toothed wheel 12 provided'with a cam, which turnsabove the heads 01 the pins I63, I64, and moreover with a toothed wheel14 or the same size which is secured with the contact arm 15 to a shaft,the heads of the pins I63, I34 playing the same part as the keys M to 43in Fig. 3. This contact arm 15 passes in synchronism with the -cam 13over a number ofcontacts 16, 11, 13, 13

which correspond to a number of press buttons 86, 31,33, 33 on akeyboard 33. Below the press buttons, which are released by the actionof springs (not represented) are provided two metal strips 3I to 32which are connected to the terminal 33 of the alternating current mainsor to a point of the motor winding. Upon depression of one of thebuttons 36, 31, 3 3, 33-the strips H and 32 are connected to the contactbelow the depressed button. The terminal 34 of the network is connectedthrough the contact 33 to another point of the motor winding. Below thepress buttons there is a number or individual contacts 36, 31, 33, 33are provided which are connected v to the contacts 16, '11, 13, 13. v n

The condenser 35 in the motor 13 can be short circuited through thesecontacts, the contact arm 15 and the strip 32, due to which the motorbegins to operate as'an' electric brake, since the initial rotary fieldchanges to an alternating field. It, for instance, the press button 31is pressed the motor 13 begins tooperate and the rotor of the motor isdrawn into the field of the stator, the contact; arm 15 now passing overthe contacts'. Upon reaching contact 11 the condenser 35 is'shortcircuited owing to which the'motor stops in this position. In this casethe cam 13 hasdepressed one or the pins I63 and I34 thus securing adefinite final position for the slide condenser. toothed rack 33 whichis engaged by a pawl II by the action of a spring 32. This pawl preventsthe condenser from returning with each succeeding depressed pin, so thatthe condenser comes to a standstill in the position determined The rodI6I has mounted ,on it a e by the longest pin passed by the cam 13. Onlywhen the final position of the cam I3 has been attained and the motor Iis thrown out by releasing the press button the condenser I60 isreleased, since the pawl 9| is lifted from the toothed rack 90 by alever 93 and a spring 94, if the rotor of the motor is no longerattracted in the field of the stator. After the desired station has beenreached the motor comes to a stand still which may be indicated by anincandescent lamp which may be switched in by means of a centrifugalcontact provided on the motor shaft. The press button is then releasedand the motor is thrown out.

Figs. 6 and 7 represent a third embodiment of the invention.

Fig. 6 is a schematical detail view of the mechanism in the receiverproper, whereas Fig. 7 shows the circuit arrangement of this form, ofconstruction.

In this form of construction the receiver proper, as well as theprevious forms of construction, comprises a number of keys,th'e'receiving set upon depression of one of these keys being tuned tothe station to which the de- I pressed key in question was previouslyadjusted. In the form of construction to be described the depression ofthe keys is effected again by means of a cam shaft provided above thekeys, but now through the intermediary of a pawl secured to each key.For each key there is provided a magnet which on bein energized attractsthe pawl secured to this key, as the result of which the key can bedepressed by a cam provided above the same.

In Fig. 7 a key board comprising a number of press buttons I2I, I22 andI23 is denoted by I; this board is separated from the receiver andplaced at a smaller or larger distance therefrom. The receiver comprisesa number of magnets I26, I21 and I20 corresponding to the number oi.keys. Moreover, the receiver comprises contacts III, I32, I33.

From each press button a conductor leads to a corresponding magnet whichin its turn is connected in series with the corresponding contact; thecircuit can be closed through a relay I which is common to allconductors, a tuning motor I36, the alternating current main Interposedbetween the terminals I31 and I38 and a common return lead to the pressbuttons.

If, for instance, the press button I 2i is depressed the said circuit isclosed through the magnet I26, the contact I3I still closed at themoment of the depression, the relay I40, the tuning motor and thealternating current mains, as result of which the magnet I26 and therelay I40 are energized and the tuning motor I36 begins to operate.

-The function of the relay I40 is to interrupt the mechanical couplingbetween the tuning motor I36 and the tuning'means and to establish amechanical coupling between the tunin motor I36 and the cam shaftprovided above the keys to be pressed. This cam shaft is designated byI02 In Fig. 6. The cam shaft I02 moves and the cams provided thereon,which are displaced in the direction of rotation with respect to oneanother and one of which is denoted by I03 in the drawing, depress thepins located below the cams. One of the keys referred to withcorresponding pawl, magnet and pin is represented in Fig. 6.

The key consists of the lever 35. The pawl is designated by IOI, themagnet by I26 and the pin by I04. The key is pivoted at 233 and bearswith a spring 240 on a clamped spring 233. Upon depression of the lever35 the desired station is chosen in the manner set out with reference toFig. 4. The reference numbers of the parts of the circuit arrangementare the same as those of corresponding parts in Figs. 4 and 7.

As soon as the press button I2I in Fig. 7 is depressed the magnet I26 isenergized, the cam shaft I02 begins to turn and the pin I04, inter alia,descends. In the meantime the magnet I20 has changed over, against theaction of a spring I05, the pawl IOI which is now in the path of the pinI 04. Due to this the pawl MI is depressed by the cam I03 through theintermediary of the pin I04, the lever 35 following this movement andopening the contact I3I connected in series with the magnet I26. Due tothis the energization of the magnet I26 ceases and the motor I36 isstopped. However, the pawl I 0| cannot be drawn back by the spring I05,this being prevented by a projecting part of the pin I 04. The motor I36is mechanically changed over to the tuning means by the relay I40 whosearmature is no as to adjust the controlling means to predetermineddiii'erent positions, an operable cam device acting upon operation tooperate the selectively operable devices in a predetermined sequence,means including said motor for operating the cam device, a control unitincluding a plurality of auxiliary selectively operable devicescorresponding to said first named plurality of selectively operabledevices, each thereof acting upon operation to first cause disconnectionof the motor from said adjustable controlling means and connectionthereof to said cam device and cause the motor to drive the cam deviceto a position at which the corresponding one of said first namedplurality of selectively operable devices is operated by the cam device,means acting on the attainment of said position to cause disconnectionof the motor from said cam device and connection thereof to saidadjustable controlling means, said motor acting upon its being coupledto said controlling means to adjust the same to the adjustment calledfor by the operated one of said first named plurality of selectivelyoperable devices.

2. In signaling apparatus including an adjustable controlling element, amotor normally coupled to said controlling element for operating thesame and. selectively operable means acting upon selective operationthereof to control the operation of the motor and thereby effect theadjustment of said element to predetermined different positions, anadjustable selector device for operating said selectively operable meansin a predetermined sequence, and auxiliary selectively operable motorcontrol means acting upon selective operation thereof to connect saidmotor to said selector device and control the -operation of the motor tothereby effect. the adjustment of said selector device to predetermineddifferent positions.

3. In signaling apparatus including an adjustable controlling element, amotor normally con- 'nected to said element for operating the same andselectively operable means acting upon selective operation thereof tocontrol the operation of the motor and thereby effect the adjustment ofsaid element' to predetermined different positicns, an adjustableselector device for operating said selectively operable means, saidselector device having a different operating position for each of saidselectively operable means, a plurality of auxiliary selectivelyoperable means corresponding respectively to the difler'ent positions Iof said selector device, each of said last named means acting uponoperation thereof to disconnect the motor from the controlling element,

connect the same to said selector device and control the operation ofthe motor so as to adjust said selector means to the corresponding oneof its positions, and means acting upon adjustment 0! the selectordevice to the selected position for re-est'ablishing the connectionbetween the motor and the controlling element.

4. In signaling apparatus including an adjustable tuning element, amotor normally connected to said tuning element ior operating the same,and a plurality of selectively operable devices auxiliary selectivelyoperable motor control means acting upon selective operation thereof toeffect disconnection of the motor from the tuning element and connectthe same to said selector device and control the operation oi the motorso as to adjust said selector device to a desired one of itspositions,and means acting upon adjustment of the selector device to the desiredposition for re-establlshing the connection between the motor and thetuning element whereby said tuning element is adjusted to the desiredposition.

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